The demand for solid surface countertops such as granite, marble, engineered stone, and Corian® have steadily risen over the past decade. As the demand for solid surface countertops, vanities, tub-decks, fire place mantles and hearths continue to grow, the more imperative it is for solid surface fabrication companies to do the work faster, without sacrificing quality, in order to meet demand. In working with solid surfaces, it is often desirable to laminate two or more pieces of material together, especially at the visible edges of countertops. By laminating pieces together, it is possible to make the finished countertop appear thicker, and to provide a more substantial edge for the application of more elegant edge treatments. For example, much of the granite comes in slabs that are only about 20 mm thick. In order to make the countertop appear thicker, a narrow strip of the slab (also known as a skirt) is laminated to all visible edges, making the slab appear to be twice as thick. Also, the edge is now more substantial, allowing more complex and interesting edge treatments to be ground or cut into the edge. For example, when a 20 mm strip is laminated to a 20 mm thick countertop, an elegant full bullnose may be ground onto the edge. The process of laminating material is a regular and necessary task for most solid surface fabrication companies. Unfortunately, because this industry is still relatively young, the technology and tools used to laminate these materials are quite crude.
Solid surface material is often sold in slabs, which, in the case of granite, may be up to 9 feet by 6 feet in size, and in some cases, even larger. Solid surfaces may also be sold in tile form. These tiles are often available in standard sizes, such as 12″×12″, 16″×16″, or 18″×18″. It will be appreciated that solid material may be available in a variety of sizes, and may represent either a natural or man-made material.
Standard c-clamps are the most common tool employed by solid surface fabricators for joining two materials. There are many problems associated with using c-clamps, including the time it takes to use them, recurring replacement costs, poor lamination quality, and increased risk of repetitive motion injuries. When laminating using conventional tools, an adhering agent is applied between two pieces of material, the pieces are manually aligned, and then c-clamps are used to press the pieces together while the adhering agent cures. To achieve an even clamping pressure, the c-clamps must be spaced evenly and close together (as little as 3″), depending on the size of the c-clamp. Each c-clamp must be tightened to approximately the same torque as all the others. Even small differences in compression may result in a poor adhesion, or in one or both material pieces breaking. Additional fabricating operations are performed on the solid surfaces after they are joined and the adhering agent has cured such as machining, cutting, grinding, sanding, and polishing. Noticeable gaps between the two materials will appear after these other fabricating operations if even clamping pressure was not achieved during the joining process. Noticeable gaps are unacceptable and the completed work may be rejected, resulting in expensive material and labor loss due to rework and replacement efforts.
The use of conventional c-clamps for laminating has several undesirable effects. For example, it takes a long time to apply all the c-clamps and often requires more than one employee to tighten all the c-clamps before the adhering agent begins to cure. Also, as the c-clamps are tightened, the glue, epoxy, or other adhering agent may be squeezed from between the pieces. This adhering agent is, by nature, sticky and difficult to work with, and permanently hardens during the curing process. In this way, the screw threads on the c-clamps get contaminated with the adhering agent, rendering them inoperable and thus requiring recurring replacement costs. In addition, due to the highly concentrated pressure point of c-clamps, one or both pieces of material are often broken. Rejections due to uneven clamping pressure are also common and are often caused by user fatigue (c-clamps not tight enough or not evenly tightened) or the c-clamps being spaced too far apart. Finally, there is also an increased risk of repetitive motion injuries due to the high number of c-clamps and the force required to tighten each c-clamp manually by hand.
The inventors of the present invention introduced the solid surface clamp in U.S. Pat. No. 7,789,379 that addressed some of these problems. This patent is incorporated herein by reference. But the '379 patent disclosed a complicated alignment system to maintain the top jaw alignment to the bottom jaw. Specifically, the alignment pin 23 (FIG. 1 of the '379 Patent) required holes bored into the both the top and bottom jaws, and was exposed to adhesives squeezing out of the seam of the bonded material. Once these adhesives dried on the alignment pin and the bored holes (in the top and bottom jaws), it would inhibit the operation of the clamp. Additionally, the alignment pin of the '379 patent required the top and bottom jaw to be larger (more material equals higher cost) to accommodate the alignment pin next to the bolt. The pin itself also needed to be larger to withstand side loading from twisting the bottom jaw. The alignment pin needed to be connected to one of the jaws by some means of attachment such as a press fit, set screw, glue, etc. This increases assembly complexity and time. Also the previous '379 patent design caused the alignment pin to exit the top jaw when the clamp was fully closed, potentially interfering with the operation of the clamp.
What is therefore needed is a more robust solid surface clamp with an alignment system that is simpler to manufacture, and protected from the damaging effects of the adhesive squeeze out.